If you're counting calories and you're not not sure how many you are taking in, finding the answer is now as easy as snapping a picture. Using a new iPhone app, Meal Snap, you can now take a picture of the meal in front of you and be told not only what food is in the meal but also the number of calories.
Does it work? Based on the reviews, although a little rusty, it does a surprisingly good job.

How does it work? From what I understand, the pictures are submitted to a human-powered service called Mechanical Turk. Once the food is identified, the information is submitted to Daily Burn, the creators of Meal Snap, and the calorie content information is found in a database.